a.
the proton tells you the atomic number
# of protons = atomic number
this is important because we can list the elements in order by the number of protons.
b.
electrons in an atom are lost/gained to make an ion. these particles are important because they are located outside of the nucleus and they are also negatively charged. since they're outside and not stuck in the nucleus, they can be transferred/shared
c. not sure, maybe electron
d. the electron is gained, lost, or shared during bonding
e. the atomic number is the number of protons while the atomic mass is the sum of the number of protons and the number of neutrons. the atomic number is also used to order elements on periodic table while atomic mass is not.
